Cultuurhistorie met toekomst: Naar een nieuw beheerplan voor ‘t Lekkere Watertje

Background Residents of the Welgelegenlaan in Driebergen-Rijsenburg have been involved with the ecological management of the spring ‘t Lekkere Watertje since the 1990s. The key principle behind this management is to conserve the scenic and natural appearance of the spring. Due to the impact of climate change on the Utrechtse Heuvelrug, the question is whether their vision and the accompanying management plan need to be adjusted. Objective and approach This research supports the local residents, joined together in the Sprengcommissie (spring committee), in the creation of a new vision and associated management plan. The objective of this research is to contribute to the conservation of the ecological and cultural heritage quality of ‘t Lekkere Watertje. The main research question is: how should the management of ‘t Lekkere Watertje in the Welgelegenlaan be updated to ensure that the ecological and cultural heritage values are maintained? To do this, the flora and fauna in the area were recorded, water readings were taken, and the residents’ experience of ‘t Lekkere Watertje was also documented. Current management and the role played by various parties were also examined. On that basis and after regular discussions with various stakeholders, the findings were translated into several recommendations. Findings ‘t Lekkere Watertje has a rich history, and residents feel connected to the greenery in their street. The residents are very involved in the management, and efforts are made to reconnect with the municipality and the water board. Residents may have different preferences, but retaining the green look and feel is unanimously considered important. The emphasis here is more on biodiversity than on a tidy streetscape. In terms of the desired appearance, the majority would prefer semi-open vegetation with some variety. The biodiversity of plants is quite high: in total, we found 171 types of plants, but this did include a number of unwanted exotics. The diversity of animals in the water is low: there are mainly species that require little from their environment. This has to do with the quality: organically water of poor quality with a low oxygen content. The banks are steep and somewhat eroded, but they do offer a place for plants to grow and various animals to hide. Extreme weather events (long periods of drought and a lot of water in a short time during heavy showers) will likely happen more often, but the impact of climate change on ‘t Lekkere Watertje is difficult to predict for us. The spring is already regularly dry.Recommendations Important measures to improve the water quality are: 1.) removing the thick layer of leaf litter from the bottom of the spring, 2.) to preserve some shade over the water course, and 3.) cleaning the overflow. As local measures will have no real chance of ensuring that there is more water in the spring throughout the year, a regional approach focused on improving the hydrological situation on the Utrechtse Heuvelrug is required (increase groundwater refreshment by stimulating infiltration and reducing extraction). Shoring is not necessary, and protecting the banks may only be applicable in highly localised sections, where there is a lot of erosion. Felling additional trees is not required as natural regeneration will also occur nor is it desirable because of the shading effect which has a positive impact on water quality by reducing solar radiation and dampening water temperature changes. However, open spaces are necessary if you want to preserve tree species that need a lot of light. The existing exotics do not generally pose a great threat to biodiversity if the current management is maintained, but specimens of swamp stonecrop (Crassula Helmsii) and giant hogweed (Heracleum mantegazzianum) must be actively controlled. Furthermore, variation in vegetation and management is desirable from a biodiversity point of view and the management does not have to be too rigid. It would be advisable for the residents, the municipality, and possibly the water board to conclude a new agreement as an expression of mutual commitment. The challenge is for residents to relate to the policies of the municipality and the water board, and for the other parties to appreciate the efforts of residents and to take their wishes seriously.